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Adaptive Digital Oscillator for Virtual Acoustic Feedback

In the domain of Virtual Acoustics research, the emulation of acoustic feedback, such as the so-called guitar howling, has been scarcely addressed. This paper takes pace from this peculiar effect to introduce a computational technique aimed at its emulation and extension to possible new scenarios of Virtual Acoustics. A nonlinear digital oscillator for real-time operation with good stability properties and low computational cost is employed to emulate guitar feedback (or guitar howling). The oscillator frequency is tuned according to a pitch detection system that adaptively tracks pitch changes in real-time. A real-time implementation of the algorithm in the Puredata environment has been developed to provide guitar howling emulation.